TL;DR
A thermostatic expansion valve is the refrigerant metering device that modulates flow into the evaporator coil based on superheat, sensed by a bulb clamped to the suction line at the coil outlet. By holding superheat near a setpoint, typically 8 to 12 degrees, it feeds the coil fully under varying loads without letting liquid slug back to the compressor.
What it means
A thermostatic expansion valve is the refrigerant metering device that modulates flow into the evaporator coil based on superheat, sensed by a bulb clamped to the suction line at the coil outlet. By holding superheat near a setpoint, typically 8 to 12 degrees, it feeds the coil fully under varying loads without letting liquid slug back to the compressor. Stuck or plugged valves mimic low charge with starved coils and high superheat, one of the most misdiagnosed conditions in residential air conditioning.
Where it sits in the glossary
Thermostatic expansion valve is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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